Cancer research arms scientists with new treatments
By Sarah Martin
April 24, 2007 10:19 p.m.
In recent years, research into cancer treatment has given doctors a new arsenal of weapons against the disease, and UCLA has often been at the forefront of these developments.
In order to develop new treatments, scientists study cancer as individual cells, collectively as tumors, or by tricking the body’s entire immune system into fighting the cancer cells.
UCLA investigators have used their research into cancer stem cells to develop biological therapies against cancer, said Dr. Harley Kornblum of UCLA’s Jonsson Comprehensive Cancer Center and UCLA’s Semel Institute for Neuroscience and Human Behavior.
“These stem cells have only recently been isolated. They are the heart of certain types of cancers ““ those are the ones treatments need to go after,” Kornblum said. “We are trying to find the genetic means that stem cells use to make more cancer cells.”
Some cancer stem cells can divide, develop, and specialize while others remain stem cells. Tumors, therefore, are abnormal growths made up of different kinds of cells that all developed from the original stem cells.
They are also hardier than other cells and are not as reactive to chemotherapies and radiation, Kornblum said.
“For many types of cancers, if they are diagnosed at a low stage (stages 1 through 3), meaning they are localized to one area of the body, they are easier targets for surgery and a minor percentage can even be cured with chemotherapy,” said Antoni Ribas, assistant professor of medicine and surgery.
According to the National Cancer Institute, chemotherapy can be used to control the spread of cancer and cure a minority of cancers, while surgery can be used to target both internal and external tumors.
But when treating stage 4 or metastatic cancers, which have spread throughout the body, options like surgery and chemotherapy become ineffective. It is at this progressed stage when most experimental processes are implemented, Ribas said.
Previous research led to experimental options including angiogenesis, which is based on the process of eliminating a tumor’s blood supply.
The latest research uses technology to search for ways to deter cancer growth, Kornblum said.
“In the Jonsson Comprehensive Cancer Center, there is a new technology called the Molecular Screening (Shared) Resource that allows researchers to conduct a large-scale screening of the many types of drugs to search for those that can be used against these hardier cancer cells,” Kornblum added.
Other immunotherapy treatment techniques, which use the body’s immune system against the cancer, are also being implemented by identifying specific proteins expressed by cancer cells. Antibodies can then target these proteins to alert the immune system of cancerous growth, Kornblum said.
“Dendric cells (are) the generals of the immune system who tell the soldier cells … what to do ““ to target cancer cells. When the immune system can be switched on to work against cancer cells, the treatment has worked well,” Ribas said.
UCLA cancer investigators are specifically working on how to keep the immune system from turning itself off, which would result in its failure to attack cancer cells. There has also been work done with an antibody that targets the off switch, which will keep the switch from being triggered, so the immune system can stay on, Ribas said.
“The next approach is to go directly to the lymphocytes (white blood cells) to genetically alter them so they can be better at finding the cancer cells,” Ribas said.
This process is based on research of HIV and its ability to attach to immune-system cells and reprogram them for the virus’ benefit, Ribas said.
“These new treatments have had good results in preliminary tests combined with chemotherapy, so the treatment is better, but still not good enough,” he said.
